Method and system for wasteless processing and complete utilization of municipal and domestic wastes

ABSTRACT

Proposed are a system and method for wasteless pyrolytic processing and complete utilization of municipal and domestic wastes. The wastes are sequentially passed through units of sorting, grinding, drying, accumulating, and sending to a pyrolysis reactor for pyrolytic treatment. The syngas produced in the pyrolysis is passed through dry cleaning, dust catching, a first wet cleaning with water, a second wet cleaning with alkali, and a floatation unit for separation of water which is purified to an extent sufficient for technical use. The purified syngas is also passed through an absorber and is then used as a working medium for a power generation unit such as a gas turbine co-generator that generates electricity. Solid products of the pyrolysis reaction, such as coke, are returned to the reactor for afterburning, and the heat of the reaction can be utilized in a dryer, or the like.

FIELD OF THE INVENTION

The present invention relates to treatment of wastes, and moreparticularly, to a method and system for wasteless processing andcomplete utilization of solid municipal and domestic wastes by pyrolytictreatment.

BACKGROUND OF THE INVENTION

The disposal of municipal, industrial, agricultural and other types ofwastes is a problem that continues to grow with the increase ofpopulation and with growth of production, especially in the industriallydeveloped countries.

The USA generates 11 billion tons (10 billion metric tons) of solidwastes each year. Solid wastes are waste materials that contain lessthan 70% water. This class includes such materials as household garbage,some industrial wastes, some mining wastes, and oilfield wastes such asdrill cuttings. Liquid wastes are usually wastewaters that contain lessthan 1% solids. Such wastes may contain high concentrations of dissolvedsalts and metals. Sludge is a class of wastes between liquid and solid.It usually contains between 3% and 25% solids, while the rest of thematerial is water-dissolved materials.

Federal regulations classify wastes into three different categories,such as non-hazardous wastes (e.g., a household garbage), commonhazardous wastes (such as those having ignitability or reactivity) andspecial hazardous wastes (e.g., radioactive and medical).

There are many different methods of disposing of wastes of which mostcommon is disposing to landfills. In a modem landfill, refuse is spreadthin, and the compacted layers are covered by a layer of clean earth.

Another method of wastes disposal is incineration. The myth that burningmakes wastes disappear has lead to incineration emerging as a widelyused method for disposing many kinds of wastes, including hazardouswastes. However, along with elimination of the wastes, incineratorsgenerate very toxic gases. Moreover, incinerator ashes are contaminatedwith heavy metals, unburned chemicals, and new chemicals formed duringthe burning process. These ashes are then buried in landfills or dumpedin the environment. In other words, incineration is a method whereindustry can break down its bulk wastes and disperse it into theenvironment through air, water, and ash emissions. Thus, the industrymasks today's waste problems and passes them onto future generations.

Existing data shows that burning hazardous wastes, even in“state-of-the-art” incinerators, produces heavy metals, unburned toxicchemicals, and generates new pollutants—entirely new chemicals formedduring the incineration process.

An alternative method of waste disposal is pyrolysis of the wastes.Pyrolysis is the chemical decomposition of materials by heating in theabsence of oxygen. Many different methods and apparatus are known in theart for pyrolytic processing of wastes.

For example, U.S. Pat. No. 4,308,807 issued in 1982 to S. Stokesdiscloses an apparatus for pyrolytically treating municipal and otherwastes composed of solid heat-decomposable materials by radioactiveheating from an open flame and convective heating. The invention isaimed at a recovery of a part of an initial energy input. The source ofinitial heat energy input can vary from gasification of renewable fuelsuch as wood chips and the like, to burning of a primary fuel butpreferably augmented by burning of at least a portion of the gaseouspyrolytic decomposition gases produced as a result of treatment of thewastes. The apparatus is capable of handling the wastes both prior toand after the pyrolysis process. The pyrolysis temperature is relativelylow and ranges from 250° C. to 600° C. The untreated wastes are drieddirectly in the pyrolysis reactor. By-products contain liquid fuel,e.g., oil. Although the heat generated by the apparatus is reused in thewaste-processing system, the apparatus does not generate thermal energyas its final product. Another disadvantage is that gas produced in theprocess is discharged into the atmosphere without preliminary cleaning.

U.S. Pat. No. 5,678,496 issued in 1997 to D. Buizza, et al. describes amethod and a plant for pyrolytic treatment of wastes that containorganic materials, particularly municipal solid wastes. The methodcomprises loading the wastes onto transport trolleys, inserting thetrolleys with the waste into a treatment tunnel that has a pyrolysischamber, carrying out pyrolysis of the wastes by indirectly heating thewastes to a temperature of 500° C. to 600° C., discharging thegaseous-phase substances generated by the pyrolysis from the chamber,and removing the trolleys from the tunnel for unloading the solidresidues remained in the trolleys. The gas obtained as a result ofpyrolysis is subjected to pre-cleaning by bicarbonate treatment thatinvolves the use of nucleating and/or adsorbent agents, such as sodiumbicarbonate or activated charcoal fines. The pre-cleaned gas isdissipated into the atmosphere, while the carbon residue of pyrolysis isutilized.

U.S. Pat. No. 5,868,085 issued in 1999 to A. Hansen, et al. discloses asystem for pyrolysis of hydrocarbon constituents of waste material. Thesystem includes a treatment unit featuring a retort with an ellipsoidalcross-section forming a first retort half and a second retort half. Thematerial to be treated is selectively deposited in only one half of theretort at a time during any given period of system operation This isdone to avoid abrasion and wear of the half not in use, thus prolongingthe life of the retort component. For improving efficiency of thesystem, gases that formed in the pyrolysis are retuned directly into theinterior of the retort. Prior to discharge into the atmosphere, thegaseous products of pyrolysis are cleaned from pollutants by using aplurality of selectively detachable gas injection tubes, which providefuel for thermal oxidation of the gases. Each injection tube can beremoved for cleaning independently of any other injection tube, andremoval can be accomplished without disrupting operation of the system.The system is provided with a dryer that uses solar energy, whichsignificantly limits the areas where the system can be used.

U.S. Pat. No. 6,178,899 issued in 2001 to M. Kaneko, et al. describes aninstallation for pyrolytic treatment of industrial and household wastesfor carbonizing waste-containing organic substances in a conditionsealed from an air so as to separate the wastes into a pyrolysis gas anda pyrolysis residue. The pyrolysis process is carried out at a hightemperature in the rage of 1000° C. to 1200° C. In a gas cracking stepof the process, pyrolysis gas is reacted with an oxide component forthermally decomposing high molecular hydrocarbon in the pyrolysis gas.The heat generated by the oxidization reaction produces a cracked gasthat contains low molecular hydrocarbon. The product then passes througha residue cooling step for cooling and solidification of the pyrolysisresidue. The obtained solid residue is mechanically crushed and sortedfor obtaining a pyrolysis char consisting essentially of a pyrolyzedorganic substance and inorganic components. The obtained pyrolysis charis burned at a high temperature by being mixed with fuel and oxygen orair for melting and gasification of the carbon component to obtain agasified gas that contains low molecular hydrocarbon. Thus, thepyrolysis gas and the pyrolysis residue obtained from the pyrolysisfurnace are treated separately. The cleaned gas obtained in the processis stored in a gas holder and can be supplied to a gas engine, a boiler,the pyrolysis chamber, or any other unit as required. Although the gasis cleaned in several steps, the system does not provide cleaning fromCO₂, and this does not allow increase of the calorie-content in theproduced gaseous fuel.

U.S. Patent Application Publication No. 20059939650 published in 2005(inventors C. Cole, et al.) describes a pyrolytic waste-treatmentreactor supported in a manner that causes minimal movement or flexing ofthe chamber under effect of temperature changes. Wastes are mixed in thereactor by means of a single bladed shaft.

U.S. Pat. No. 6,619,214 issued in 2003 to W. Walker discloses a methodand apparatus for treatment of wastes. The apparatus comprises fourmajor cooperating subsystems, namely a pyrolytic converter, a two-stagethermal oxidizer, a steam generator, and a steam turbine driven by steamgenerated by the steam generator. In operation, the pyrolytic converteris heated without any flame impinging on the reactor component, and thewaste material to be pyrolyzed is transported through the reactionchamber of the pyrolytic converter by a pair of longitudinallyextending, side-by-side material transporting mechanisms. However, thesystem is designed only for afterburning of the gas and does not teachthe subsequent use of the gaseous product as a fuel for a powergenerator. Although the waste feeder is made in the form of two parallelaugers, the latter transport the wastes without effective mixing.

U.S. Patent Application Publication No. 20070113761 published in 2007(inventors C. Cole, et al.) discloses a pyrolytic waste-treatmentreactor with dual knife gate valves. The apparatus has a thermalchamber, a feed-stock inlet coupled to the thermal chamber for feedingthe waste material into the thermal chamber, a heater that heats thethermal chamber, and at least one dual knife gate valve positioned inthe apparatus for restricting the passage of the waste material throughan interior space of the apparatus and for limiting introduction of gasinto the thermal chamber. The dual knife gate valve has at least onemovable blade that moves toward another blade. The wastes are movedwithout effective mixing.

U.S. Patent Application Publication No. 20070186829 published in 2007(inventors C. Cole, et al.) discloses a variable speed pyrolytic wastetreatment system comprising a pyrolysis chamber and a movement mechanismadapted to move waste through the pyrolysis chamber at different speedsalong the length of the pyrolysis chamber. The main conception of thissystem is to vary the rate of movement of material through a pyrolysischamber. In particular, material might move at a slower rate when itfirst enters the chamber and move at a faster rate after it has beenheated and as is moved toward the chamber exit. The movement mechanismcontains two shafts that are provided with screwed which covert intoblades. The shafts rotate in opposite directions and therefore take thematerial from the central area and transfer it to the periphery of thechamber.

U.S. Patent Application Publication No. 20070289507 published in 2007(inventors W. Parrott, et al.) discloses a system, method and apparatusfor pyrolyzing wastes to produce a gaseous fuel and any remainingmaterial in a plurality of chambers The gaseous fuel may be sent to anafterburner where other elements may be added to generate heated gashaving a predetermined temperature. The heated gas may be used in avariety of devices, such as a heat exchanger, or the like. However, thesystem is not provided with a material crusher and dryer.

U.S. Patent Application Publication No. 20080236042 published in 2008(inventor J. Summerlin) discloses a rural municipal waste-to-energysystem and method converting waste to fuel gas through anaerobicdigestion (AD) and pyrolysis/gasification. Fuel gases derived during theprocesses are combined and used to generate electricity. The amount ofmunicipal solid wastes normally collected by a municipality may beinadequate in volume to produce enough fuel gas with which to generateelectricity sufficient to serve the entire community. It may benecessary, therefore, for additional wastes from the surrounding area tobe included. The municipality must have its own public electric utilityto be able to charge rates necessary for profitability. A waste-dryingstep is not included, and the syngas is mixed with a biogas without anypreliminary cleaning.

U.S. Patent Application Publication No. 20090020052 published in 2008(inventors F. Becchetti, et al.) describes a process for solid wastetreatment, and particularly municipal solid waste, with recovery of thethermal energy, which is based on the general pyrolysis process modifiedin order to improve, on the one hand, the energy yield and, on theother, to reduce the quantity of unusable solid residues to be sent tothe waste disposal, the unusable solid waste being limited to 10-15% ofthe total weight of the initial residue. The process and relative plantinclude a boosted treatment of the incoming waste, with a preliminaryseparation into three solid fractions, the first one of which isseparately subjected to a preliminary drying step and the third oneundergoes further shredding. The process and relative plant also includea section for recovering energy from the pyrolysis coke, wherein thelatter is subjected to a thermochemical treatment with the production ofa further quantity of synthesis gas. The system offers drying only ofthose wastes the fraction of which does not exceed 80 mm, while wastefractions ranging from 80 mm to 300 mm are not subject to drying. Thesyngas is subjected to afterburning without pre-cleaning, although theflue gas obtained after afterburning allows generation of steam for usein a boiler and is cleaned prior to exhaust into the atmosphere.Electricity is generated by a steam turbine. The patent does not teachutilization of the coke residue that remains after the process.

Known in the art also are plasma waste processing systems (see, e.g.,U.S. Pat. No. 7,394,041 issued in 2008 to W. Choi). However, the plasmaprocess is applicable only to treatment of gaseous products. Therefore,prior to treating the wastes by plasma, it is necessary to covert thesolid wastes into a gaseous state. For example, U.S. Pat. No. 5,544,597issued in 1996 to S. Camacho discloses plasma pyrolysis andvitrification of municipal wastes. Municipal mixed solid wastes aredelivered to a processing facility where it is compacted before beingplaced into a reactor. The compaction apparatus serves to remove most ofthe air and some of the water from the waste as well as to seal thereactor against air infiltration. A transfer apparatus, in response to asignal relating to the height of waste in the reactor, sequentiallydeposits blocks of compacted waste in the top of the reactor when theheight is low. The reactor has a pivotally and extensively mountedplasma arc torch as a heat source which is effective to pyrolyze organicwaste components to generate desired by-product gases. Air and steam areadded in controlled quantities to improve the operational efficiency andthe by-product gas composition. The residual materials which do notpyrolyze are melted and cooled into a substantially inert vitrifiedmass.

A disadvantage of plasma pyrolysis systems is that such systems requiregasification of solid wastes which is associated with additionalexpenses. Another problem is associated with the generation of hazardousgases such as dioxins and furanes which are formed after cooling of theplasma products to a temperature below 500° C., if the wastes weretreated at temperature above 1200° C. for less than 2 sec.

Another disadvantage of plasma systems is that such systems work attemperature of 2500 C to 5000 C. Such temperatures deterioratestructural materials of the system and lead to frequent and expensivemaintenance and repairs.

Analysis of the known waste-processing systems based on pyrolytictreatment of wastes shows that a majority of these systems involvesafterburning of the syngas either in a separate burning chamber or in aseparate section of the pyrolysis reactor. The flue gases obtained as aresult of afterburning are used for generation of steam or electricenergy in steam turbines that have energy-generation efficiency lowerthan gas-turbine co-generators. Some systems offer to use the syngas forgeneration of energy in gas-turbine generators. However, in some casesthe syngas is used as a component for a mixture with biogas withoutpre-cleaning, and in other cases the syngas is not separated from CO₂and therefore has low energy-generation efficiency. Another disadvantageof the known waste-processing systems is a lack of an efficientmechanism for feeding and mixing materials in pyrolysis chambers, arelatively high metal-to-power ratio in the structure of the pyrolysischamber and, hence, high manufacturing cost, and incomplete cleaning ofthe gases, which are exhausted through the upper channel of the chambertogether with the syngas, from fine waste particles.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the invention to provide a novel method and systemfor wasteless pyrolytic processing and complete utilization of municipaland domestic wastes. It is another object to provide the aforementionedsystem that allows a high degree of purification of gas and moreefficient generation of energy in gas-turbine co-generators. It is afurther object to provide the aforementioned method and system thatseparate CO₂ from the syngas and utilize the separated CO₂ as anadditional commercial product along with decrease in concentration ofharmful components in the gas exhausted to the atmosphere. Still anotherobject is to provide the aforementioned system that does not requireseparate collection of wastes of different types. One more object is toprovide the above system that does not leave by-products such as acoking residue. Still another object is to provide the aforementionedsystem that is capable of working in a self-contained mode and at thesame time producing energy for external consumers.

The waste-processing system of the invention is intended for processingsolid municipal and domestic wastes (hereinafter referred to merely as“wastes”). The system comprises the following modules connected inseries: a waste pre-treatment and feed module, a pyrolysis reactor, asyngas cleaning module, and an energy generation unit.

The waste pre-treatment and feed module consists of a waste-sorting unitcapable of sorting the untreated wastes and simultaneously removingthose waste components that have low energy potential and do not containhydrocarbons. In this unit, the sorted wastes can be combined withadditional wastes having high content of hydrocarbons. Other unitsincluded into the waste pre-treatment and feed module comprise awaste-mixture grinder, a ground-waste drier, and a dry-waste accumulatorthat stores the waste dried to a predetermined level and has means forcontinuing supply of the ground and dried waste to the pyrolysisreactor. The latter has a retort that forms a pyrolysis chamber which isisolated from access of oxygen and contains a pair of waste-feedingscrews.

Mechanisms of loading of the wastes into the pyrolysis reactor and ofunloading of solid products of the reaction, such as coke, are similarto each other in that each of these mechanisms comprises an upper andlower slide valves or gates. Waste loading mechanism is installed on thefront or proximal cover of the pyrolysis reactor, and the coke unloadingmechanism is installed on the rear or distal cover of the pyrolysisreactor. The wastes fall from the waste accumulator onto the closedupper gate. Then the upper gate is opened, and the wastes fall onto thelower gate. After accumulation of a predetermined amount of the wastes,the upper gate is then closed, and the lower gate is opened allowing thewastes to fall onto the loading screw that moves the wastes to aspring-loaded gate. When the wastes are compacted to a degree thatexceeds the holding threshold of the spring-loaded gate, the latter isshifted away under waste pressure and let the load to enter the spacebetween the thread surfaces of the waste-feeding screws inside theinterior of the retort. Such a two-gate spring-loaded gate preventssmall particles of the wastes from *being carried away into the oxidizerwithout being pyrolyzed, decreases penetration of oxygen-containingatmospheric air into the retort. The waste-feeding screws have avariable pitch, which decreases in the direction of movement of thematerial. This allows for reducing the volume occupied by the wastes andthus to reduce the volume of air in the wastes. The air-displacementforce is adjusted by the mass of a cover secured on an axle.

The reactor-unloading mechanism has a similar two-gate mechanism butdiffers from the loading mechanism in that the material unloaded fromthe reactor is coke and that it does not have a feed screw and aspring-loaded gate.

In a cross-section, the retort has a three-lobe shape with two lowerlobes that form cavities for respective waste-feeding screws and anupper lobe that forms a syngas-passage cavity with vertical walls. Thelongitudinal axis of the upper cavity is horizontal. The waste-feedingscrews are driven into rotation from a hydraulic motor via a gearreducer. The lower cavities and the waste-feeding screws have a taperedshape with peripheral surfaces of the screw threads located in closeheat-transfer proximity with the inner walls of the retort. The threadsof the waste-feeding screws overlap each other without physical contactand leave a space between the thread surfaces so that the feederoperates similar to a gear pump by effectively mixing the waste materialwhile feeding it forward to the distal end of the pyrolysis reactor,i.e., to the end that is located on the side of the syngas cleaningmodule. The aforementioned gap prevents the wastes from accumulationinside the retort. Furthermore, the aforementioned gap is separated intotwo parts by an edge that divides the flow of the mixed wastes into twoseparate sub-flows. This provides movement of the wastes along the wallsof the pyrolysis reactor and prolongs time of contact of the wastes withthe hot walls of the retort, thus improving efficiency of the process.The waste-feeding screw is assembled from several sections that can beseparated from each other and are connected through the use of conicalthreaded elements. The screw shaft is hollow and its interior isprovided with thermal insulation. The areas of connection of the screwelements are free of the insulation for more efficient cooling of theseportions of the waste-feeding screws. The cooling medium is air that ispassed through the hollow screws through inlet and outlet devicesinstalled at the respective ends of each waste-feeding screw.Longitudinal axes of the tapered waste-feeding screws are inclined withthe distal ends (i.e., the ends at the unloading position of thechamber) being lower than the proximal ends (i.e., ends at the loadingposition of the chamber). The waste-feeding screws are not only taperedand inclined in the vertical plane, but also converge in a horizontalplane. More specifically, the inclination angle of the screws in thevertical plane down from horizontal level ranges from 1.5° to 3° and hasan optimal value of 2.04°. The convergence angle of screws in thehorizontal plane from proximal ends to the distal ends ranges from 1.8°to 3° and has an optimal value of 2.22°. The maximal diameter of thescrew thread at the proximal end ranges from 1000 to 1200 mm with theoptimal value of 1200 mm. The minimal diameter of the screw thread atthe distal end ranges from 550 mm to 650 mm with the optimal value of600 mm. The aforementioned mounting angles can be adjusted in the rangeof ±30 minutes, preferably ±10 minutes. Adjustment of the angles makesit possible to set the gaps between the walls of the retort and thescrews. Adjustment is carried out with the use of eccentric bushesinstalled in support units of the respective covers.

The three-lobed retort is surrounded by an external casing that has ahexagonal cross-section and walls made from a refractory material. Theinterior space between the inner walls of the external casing and theouter surface of the retort forms a furnace for burning a fuel gas thatgenerates heat for heating the interior of the pyrolysis chamber andhence for causing a pyrolytic exothermic reaction inside the chamber.The fuel gas may comprise an externally supplied natural gas or gasgenerated as a result of pyrolysis. The fuel gas is supplied to theburners arranged under the lower cavities of the retort. The thermalenergy generated by burning the fuel gas in the furnace is transmittedto the interior of the pyrolysis chamber through the chamber walls. Thepyrolysis temperature in the chamber ranges from 800° C. to 1000° C.,preferably from 850° C. to 900° C. Automatic control keeps thetemperature with the prescribed optimal range and shuts the burner on oroff, depending on the temperature conditions.

Among the burners, at least one may be designated for burning the cokeobtained as a result of pyrolysis. In this case, the burning chamber ofthe pyrolysis reactor does not need a supply of an external heat. Thecoke obtained in the rector is purified in a centrifuge from residue ofmetals, glass, etc. and is burned on the aforementioned burner. Thus,the reactor may operate on gas fuel and coke without supply of theexternal heat.

The outlet end of the retort is connected to a centrifuge that receivesthe coking carbonaceous pyrolysis residue from the retort of thepyrolysis reactor and separates those low-energy components that havenot been separated from the waste mix at the earlier stages from thecoking carbonaceous residue of the pyrolysis process. Another functionof the centrifuge is mixing of the dehydrated tar and chlorine-,fluorine-, and sulfur-containing components separated from the syngastogether with the mixture of the coking carbonaceous pyrolysis residue.

The pyrolysis reactor is further provided with means-for simultaneousremoval and supply of heat and/or flue gases obtained in the pyrolysisreaction to the ground-waste drier of the waste pre-treatment and feedmodule.

The pyrolysis reactor is also provided with means for simultaneousremoval of syngas obtained in the pyrolysis reaction and for sending aportion of this syngas to the furnace of the reactor as an additionsource of heat.

The syngas cleaning module comprises a dry cleaning unit with a dustcatcher (not shown) and a wet-syngas cleaning stage where the syngas iscleaned from tar and chlorine-, fluorine, and sulfur-containingadmixtures. The wet-cleaning stage consists of a first wet syngascleaner, where the syngas is cleaned with water, and a second wet syngascleaner, where the syngas is cleaned with an alkali. A gas cooler, whichis located between the dry cleaning unit and the first wet syngascleaner, is intended for cooling the syngas prior to the supply of thegas to wet cleaning.

The wet syngas cleaners are connected to a floatator that separateswater from the remaining impurities. The mixture of water withimpurities is sent to a floatator via pipes. This unit produces processwater that can be further utilized. The outlet end of the floatator isconnected to the centrifuge of the pyrolysis reactor and may supply thedehydrated tar, chlorine-, fluorine, and sulfur-containing componentsthrough the centrifuge, where these components are combined with themixture of the coking carbonaceous residue of the pyrolysis process.Then this mixture is sent back to the furnace of the pyrolysis reactorfor burning together with the aforementioned mixture and thus formaintaining the working temperature of pyrolysis inside the reactor.

The wet-cleaning stage is also connected to an absorber, which separatesa CO₂-saturated aqueous solution and thus for separation of at least areusable gaseous carbon dioxide from the syngas. The CO₂-saturatedaqueous solution is then delivered to the disorber for subsequentdecomposition of the solution into CO₂ and processing water.

The energy-generation module of the system is made in the form of agas-turbine co-generator that is connected to the outlet of the absorberand generates electric and heat energy by burning syngas purified frompossible contaminated components and obtained from the absorber. Theco-generator uses the syngas obtained from the absorber as a workingmedium. The electric energy is transmitted to customers via atransformer substation and power lines.

The system operates in a continuous mode as follows.

First the municipal and domestic wastes that are intended for processingare sorted by means of the waste-sorting unit capable of sorting thewastes and simultaneously removing those waste components that have lowenergy potential and do not contain hydrocarbons. If necessary, thesorted wastes are combined in this unit with additional wastes havinghigh content of hydrocarbons. The presorted wastes are then fed to thewaste-mixture grinder where the wastes are ground to a predeterminedsize, e.g., 50 mm. The grinder may be of any type if it is able to grindthe treated waste. The ground wastes are fed to a dryer where the groundwastes are dried at a predetermined temperature, e.g., in the range offrom 150 to 250 ° C. until the content of moisture in the wastes reachedthe level of about 20%. The dryer may be of a drum-type and may operateon the basis of the heat obtained from the output of the pyrolysisreactor. From the dryer the wastes are sent to the dry-waste accumulatorthat stores the waste dried to a predetermined level and has means forcontinuing supply of the ground and dried waste to the pyrolysisreactor. The mechanisms of loading of the wastes into the pyrolysisreactor feeds the reactor by means of the feeding screw via theaforementioned double-gate structure. The wastes fall from the wasteaccumulator onto the closed upper gate. After accumulation of apredetermined amount of the wastes, the upper gate is opened, and thewastes fall onto the lower gate. The upper gate is then closed, and thelower gate is opened allowing the wastes to fall onto the loading screwthat moves the wastes to a spring-loaded gate. When the wastes arecompacted to a degree that exceeds the holding threshold of thespring-loaded gate, the latter is shifted away under waste pressure andallows the load to enter the interior of the retort.

In the pyrolysis reactor, the wastes are subjected to a pyrolysistreatment by being heated without access of oxygen to a temperature inthe range of 800° C. to 1000° C. The product is conveyed from theloading side to the unloading side of the reactor due to rotation of thetapered screws that converge in the horizontal plane and are inclined inthe downward direction in the vertical plane. The material istransported through the gap between the threads of the screws and at thesame time is effectively mixed by the rotation of the screws.

As a result of the pyrolysis, the treated product is decomposed into asolid phase (a mixture of carbon residue that contains coke and tar, anda gaseous phase (syngas). A part of the heat and flue gas developed inthe pyrolysis reactor furnace is sent to the waste drier. A part of thesyngas developed in the pyrolysis reactor is sent to the burners of thereactor for use as an additional fuel for maintaining the pyrolysisprocess temperature at a required level. The coking carbon residue issent to a centrifuge for purification and separation of low-energyresidue that does not contain hydrocarbons and that could not be removedfrom the wastes at the sorting stage. The carbon residue (with 2 to 10%of carbon) is then sent back to the burners of the reactor forafterburning.

From the pyrolysis reactor, the syngas is sent to the dry-cleaning unitwith the dust catcher where the level of dust in the syngas is reduced,and the syngas is then passed through the first stage of the wetscrubber when the syngas is cleaned by a flow of water from tar andchlorine-, fluorine, and sulfur-containing admixtures. The syngas isthen fed to the second wet-stage of scrubbing with subsequent removal ofthe separated impurities. From both wet-stages of scrubbing, the mixtureof water with impurities is sent to a floatator that produces processwater suitable for further appropriate use. Meanwhile, dehydrated tarand mixture of dehydrated impurities are sent to a centrifugal pump formixing with the coking carbonaceous residue of the pyrolysis process andfrom there to the reactor burners for afterburning.

The syngas purified from the tar and the chlorine-, fluorine, andsulfur-containing admixtures is fed to an absorber that produces aCO₂-saturated aqueous solution, which is sent to the disrober withsubsequent decomposition of the solution into CO₂ and processing water.The purified syngas is fed to a power co-generator (of a piston or agas-turbine type), where the gas is used as the co-generator fuel. Theco-generator produces electric energy that can be used for purposesrequired, while heat that was removed from the co-generator can beutilized or converted in accordance with specific demand.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block-diagram of the system for processing and utilizingsolid industrial, municipal, and domestic wastes by pyrolytic treatment.

FIG. 2 is a cross-sectional view of the pyrolysis reactor along lineII-II of FIG. 3.

FIG. 3 is a longitudinal sectional view of the reactor along lineIII-III of FIG. 2.

FIG. 4A is a top view of two waste-feeding screws used in the pyrolysisreactor.

FIG. 4B is a fragmental partially sectional longitudinal view of a screwelement.

FIG. 4C is a cross sectional view along line IVC-IVC of FIG. 4B.

FIG. 4D is a three-dimensional view of an eccentric bush on the shaft ofthe screw used for adjusting the gap between the outer surface of thescrew and the inner surface of the retort in the pyrolysis reactor ofthe invention.

FIG. 5 is a sectional view of the reactor loading (unloading) mechanism.

FIG. 6 is a flowchart that shows the process steps.

DETAILED DESCRIPTION OF THE INVENTION

As has been mentioned above, the invention relates to a method andsystem for processing and utilizing solid municipal and domestic wastesby pyrolytic treatment.

A block-diagram of the system of the invention for processing andutilizing solid municipal and domestic wastes by pyrolytic treatment isshown in FIG. 1.

The system, which as a whole is designated by reference numeral 20,comprises the following main modules connected in series: a wastepre-treatment and feed module 22, a pyrolysis reactor 24, a syngascleaning module 26, and an energy generation unit 29.

The waste pre-treatment and feed module 22, in turn, consists of a wastereception site 21, a linear conveyor T1, a waste-sorting unit or asorter 28 that received the untreated wastes from the linear conveyor T1and is capable of sorting untreated wastes and simultaneously removingthose waste components that have low energy potential and do not containhydrocarbons. In this unit, the sorted wastes can be combined withadditional wastes having high content of hydrocarbons. Other unitsincluded into the waste pre-treatment and feed module 22 comprise awaste-mixture grinder 30, which is connected to the sorter by a secondlinear conveyor T2, a ground-waste drier 32, and a dry-waste accumulator34 that stores the waste dried to a predetermined level and has meansfor continuing supply of the ground and dried waste to the pyrolysisreactor 24. Reference numeral 32 a designates a pipe that connects theoutlet of the reactor 24 to the dryer 32 for sending a part of the fluegases used to heat the reactor from the reactor furnace to the dryer forthe supply of addition heat.

As a result of a pyrolysis reaction that takes place in the pyrolysisreactor 24, the wastes are decomposed at least into a syngas and solidproducts of pyrolysis, such as coke.

A cross-sectional view of the pyrolysis reactor 24 along line II-II ofFIG. 3 is shown in FIG. 2. FIG. 3 is a longitudinal sectional view ofthe reactor 24 along line III-III of FIG. 2. The reactor 24 has a retort36 that forms a pyrolysis chamber 38, isolated from access of oxygen,and contains a pair of waste-feeding screws 40 and 42. Bothwaste-feeding screws 40 and 42 are seen in FIG. 4A, which is a top viewof the waste-feeding screws.

A mechanism 39 for loading of the wastes into the pyrolysis reactor 24is shown in FIG. 5. The mechanism 39′ for unloading of solid products ofthe reaction, such as coke, respectively, is similar to that shown inFIG. 5 and therefore is not shown and not considered separately. Eachabove-mentioned mechanism comprises upper and lower valves, e.g.,sliding gates 44 and 46, which are shown in FIG. 5. The waste-loadingmechanism 39 is installed on the front or proximal cover 48 (FIG. 3) ofthe pyrolysis reactor 24, and the coke-unloading mechanism (not shown)is installed on the rear or distal cover 50 of the pyrolysis reactor 24.In the modification shown in FIG. 5, the gates 44 and 46 are drivenlinearly into and from the open and close positions by respectivepneumatic cylinders 41 and 43, the piston rods 41 a and 43 a of whichare connected to respective gates 44 and 46.

The wastes fall from the waste accumulator 34 (FIG. 1) onto the closedupper gate 44 (FIGS. 3 and 5). Then the upper gate 44 is opened, and thewastes fall onto the lower gate 46. After accumulation of apredetermined amount of the wastes, the upper gate 44 is then closed,and the lower gate 46 is opened allowing the wastes to fall onto thefeeding screw 52 (FIG. 3) that moves the wastes to a spring-loaded gate54 installed at the inlet opening of the front cover 50 of the reactor24 (FIG. 3).

When the wastes are compacted to a degree that exceeds the holdingthreshold of the spring-loaded gate 54, the latter is shifted away underwaste pressure into a position shown in FIG. 3 by imaginary line 54 aand allows the load to enter the space between the thread surfaces 60(FIG. 4A) of the waste-feeding screws inside the retort 36. Such atwo-gate spring-loaded gate prevents small particles of the wastes frombeing carried away into the oxidizer without being pyrolyzed andprevents penetration of oxygen-containing atmospheric air into theretort. The waste-feeding screws 40 and 42 have a pitch that decreasesin the direction of movement of the material. This is shown in FIG. 4B,which is a fragmental longitudinal partially sectional view of a screwelement. As can be seen from FIG. 4B, the waste-feeding screw 40 (whichis the same as the waste-feeding screw 42) has the pitch that decreasesin the direction of movement of the material. In other words, pitch P1is greater than pitch P2, and pitch P2 is greater than pitch P3, etc.The diminishing pitch makes it possible to reduce the volume of thewaste being treated and thus to reduce the volume of air contained inthe treated wastes. The force of air displacement can be adjusted by themass of a pivotal spring-loaded gate 54 pivotally supported by an axle54 b (FIG. 3).

As has been mentioned above, the reactor unloading mechanism 39′ issimilar to the loading mechanism, except that the material unloaded fromthe reactor is coke. In view of the similarity with regard to theloading mechanism, the unloading mechanism 39′ is not described indetail.

As can be seen from FIG. 2, in a cross-section the retort 36 has athree-lobe shape with two lower lobes 36 a and 36 b that form cavitiesfor respective waste-feeding screws 40 and 42 and an upper lobe 36 cthat has vertical walls 36 d and 36 e and that defines a syngas-passagecavity 36 f. The screws are driven into rotation from a hydro motor 56via a gear reducer 58 (FIG. 3).

As can be seen from FIG. 2, the waste-feeding screws 40, 42 have taperedshapes with helical peripheral surfaces of the screw threads 40 a and 42a located in close heat-transfer proximity with the inner wall 36 c ofthe retort 36. The threads 40 a and 42 a of the waste-feeding screwsoverlap each other (FIG. 4A) without physical contact and leave a space60 (FIG. 4) between the helical surfaces of the threads 40 a and 42 asurfaces so that the feeder, formed by the waste-feeding screws 40 and42, operates similar to a gear pump by effectively mixing the wastematerial while feeding it forward to the distal end of the pyrolysisreactor 24, i.e., to the end that is located on the side of the syngascleaning module 26 (FIG. 1).

The aforementioned gap 60 prevents the wastes from accumulation insidethe retort 36. Furthermore, the aforementioned gap 60 is separated intotwo parts by an edge 61 that divides the flow of the mixed wastes intotwo separate sub-flows. This provides movement of the wastes along thewalls of the retort 36 and prolongs time of contact of the wastes withthe hot walls of the retort 36, thus improving efficiency of theprocess.

Each waste-feeding screw is assembled from several sections of the typeshown in FIG. 4B that can be separated from each other and are connectedthrough the use of conical threaded elements 43. As shown in FIG. 4C,which is a cross-section along line IVC-IVC of FIG. 4B, thewaste-feeding screw 40 (42) is hollow and its interior 45 is providedwith thermal insulation 47. The areas of connection of the screwelements are free of the insulation for more efficient cooling of theseportions of the waste-feeding screws. The cooling medium is air that ispassed through the interior 45 of the hollow waste-feeding screws viainlet and outlet devices 73 a and 73 b installed at loading side andunloading side of the retort, respectively.

Longitudinal axes X1 and X2 (Fig. of the tapered waste-feeding screws 40and 42 are inclined (FIG. 3) with the distal ends 40′ and 42′,respectively (i.e., the ends at the unloading position of the chamber38), lower than the proximal ends 40″ and 42″ (i.e., ends at the loadingposition of the chamber). As can be seen from FIG. 4A, the waste-feedingscrews are not only tapered and inclined in the vertical plane, but alsoconverge in a horizontal plane (FIG. 4A). More specifically, theinclination angle a of the waste-feeding screws in the vertical plane(FIG. 3) down from horizontal level ranges from 1.5° to 3° and has anoptimal value of 2.04°. In FIGS. 3 and 4 the angles are shown in anexaggerated form. The convergence angle β of the screws 40 and 42 (FIG.4A) in the horizontal plane from proximal ends 40″ and 42″ to the distalends 40′ and 42′ ranges from 1.8° to 3° and has an optimal value of2.22°. The maximal diameter of the screw threads at the proximal endsranges from 1000 to 1200 mm with the optimal value of 1200 mm. Theminimal diameter of the screw thread at the distal ends 40′ and 42′ranges from 550 mm to 650 mm with the optimal value of 600 mm. Theaforementioned mounting angles can be adjusted in the range of ±30minutes, preferably ±10 minutes. Adjustment of the angles makes itpossible to set the gaps between the walls of the retort 36 and thescrews 40, 42. Adjustment is carried out by rotating an eccentric bush71 a of the type shown in FIG. 4D installed in support unit of therespective cover. FIG. 4D is a three-dimensional view of an eccentricbush 71 a on the shaft of the screw 40 (42) used for adjusting the gap75 (FIG. 2) between the outer surface of the screw and the inner surfaceof the retort 36 in the pyrolysis reactor 24 of the invention.

The three-lobed retort 36 is surrounded by an external casing 62 (FIG.2) that has walls 64 made from a refractory material. The interior space66 (FIGS. 2 and 3) between the inner walls of the external casing 64 andthe outer surface of the retort 36 forms a furnace for burning a fuelgas and generates heat for heating the interior of the pyrolysis chamber38 and hence for causing a pyrolytic exothermic reaction inside thechamber 38. The fuel gas may comprise an externally supplied natural gasthat may be fed to the reactor via fuel supply line 69 a (FIG. 1) or gasgenerated as a result of pyrolysis and fed to the reactor via a pipe(not shown). The syngas is supplied to the burners 68 a, 68 b, . . . 68n arranged under the lower cavities 36 a and 36 b of the retort 36. Thethermal energy generated by burning the fuel gas in the furnace 66 istransmitted to the interior of the pyrolysis chamber 24 through thechamber wall 36 a. The pyrolysis temperature in the chamber ranges from800° C. to 1000° C., preferably from 850° C. to 900° C. Automaticcontrol keeps the temperature within the prescribed optimal range andshuts the burners 68 a, 68 b, . . . 68 n on or off, depending on thetemperature conditions.

Among the burners, at least one, e.g., the burner 68 b, (FIG. 2) may bedesignated for burning the coke obtained as a result of pyrolysis. Inthis case, the burning chamber 66 of the pyrolysis reactor 24 does notneed a supply of an external heat. The coke obtained in the reactor 24is fed with a screw conveyer 70 a to a coke accumulator 70 b and fromthe latter to a centrifuge 70 c (FIG. 1), which is intended forpurification of the coke from residue of metals, glass, etc. and forsending the purified coke back to the reactor 24 for burned on theaforementioned burner 68 b. Thus, the reactor 24 may operate on gas fueland coke without supply of the external heat.

When the centrifuge 70 c (FIG. 1) receives the coking carbonaceouspyrolysis residue from the furnace 66 (FIG. 2) of the pyrolysis reactor24, it separates those low-energy components that have not beenseparated from the waste mix in the waste pre-treatment and feed module22 (FIG. 1) at the earlier stages of the process. Another function ofthe centrifuge 70 c is mixing of the dehydrated tar and chlorine-,fluorine-, and sulfur-containing components separated from the syngastogether with the mixture of the coking carbonaceous pyrolysis residue.

The pyrolysis reactor 24 is also provided with devices for simultaneousremoval and supply of a portion of syngas obtained in the pyrolysisreactor to the burners 68 a, 68 b, . . . 68 n of the pyrolysis reactor24 for use as an additional fuel maintaining the pyrolysis processtemperature.

The syngas cleaning module 26 (FIG. 1) comprises a dry cleaning unit 72with a dust catcher (not shown) and a wet-syngas cleaning stage 26 wherethe syngas is cleaned from tar and chlorine-, fluorine, andsulfur-containing admixtures. The wet-cleaning stage 26 consists of afirst wet syngas cleaner 73, where the syngas is cleaned with water, anda second wet syngas cleaner 74, where the syngas is cleaned with analkali. A gas cooler 71, which is located between the dry cleaning unit72 and the first wet syngas cleaner 73, is intended for cooling thesyngas prior to the supply of the gas to wet cleaning.

The wet syngas cleaners 73 and 74 are connected to a floatator 78 thatseparates water from the remaining impurities. The mixture of water withimpurities is sent to a floatator 78 via pipes 78 a and 78 b. This unitproduces process water that can be further utilized. The outlet end ofthe floatator 78 is connected to the centrifuge 70 c of the pyrolysisreactor 24 (FIG. 1) and may supply the dehydrated tar, chlorine-,fluorine, and sulfur-containing components through the centrifuge, wherethese components are combined with the mixture of the cokingcarbonaceous residue of the pyrolysis process. Then the mixture is sentback via the pipeline 69 b to the furnace 66 (FIG. 2) of the pyrolysisreactor 24 for burning together with the aforementioned mixture and thusfor maintaining the working temperature of pyrolysis inside the reactor24.

The wet-cleaning stage 26 is also connected to an absorber 76, whichseparates a CO₂-saturated aqueous solution and thus for separation of atleast a reusable gaseous carbon dioxide from the syngas. TheCO₂-saturated aqueous solution is then delivered to the disorber 77 forsubsequent decomposition of the solution into CO₂ and processing water.

The energy-generation module 29 (FIG. 1) of the system 20 is made in theform of a gas-turbine co-generator 30 a that is connected to the outletof the absorber and generates electric and heat energy by burning syngaspurified from possible contaminated components and obtained from theabsorber 76. The co-generator 30 a uses the syngas obtained from theabsorber as a working medium. The electric energy is transmitted tocustomers via a transformer substation 81 and power lines 83.

An operation of the system of the invention for processing and utilizingsolid municipal and domestic wastes by pyrolytic treatment in will nowbe described with reference to

FIGS. 1 and 6, where FIG. 6 is a flowchart that shows the process steps.First the municipal and domestic wastes that are intended for processingare sorted (Step 1) by means of the waste-sorting unit 28 (FIG. 1)capable of sorting the wastes and simultaneously removing those wastecomponents that have low energy potential and do not containhydrocarbons. If necessary, the sorted wastes are combined in this unitwith additional wastes having high content of hydrocarbons.

The metals, glass, and similar solid impurities separated at this stageare removed and sent to recycling (Step 2).

The presorted wastes are then fed to the grinder 30 (Step 3) where thewastes are ground to a predetermined size, e.g., 50 mm. The groundwastes are then fed to a dryer 32 (Step 4) where the ground wastes aredried at a predetermined temperature, e.g., in the range of from 150 to250 ° C. until the content of moisture in the wastes reached the levelof about 20%. The dryer 32 may operate on the basis of the heat obtainedfrom the output of the pyrolysis reactor 24.

From the dryer 32 the wastes are sent to the dry-waste accumulator 34(FIG. 1) that stores the waste dried to a predetermined level and hasmeans for continuing supply of the ground and dried waste to thepyrolysis reactor 24.

Mechanisms of loading the wastes into the pyrolysis reactor feed thereactor 24 by means of a feed screw (FIG. 3) via the aforementioneddouble-gate arrangement. The wastes fall from the waste accumulator 34onto the closed upper gate 44 (FIG. 5). After accumulation of apredetermined amount of the wastes, the upper gate 44 is opened, and thewastes fall onto the lower gate 46. The upper gate 44 is then closed,and the lower gate is opened allowing the wastes to fall onto theloading screw 52 (FIG. 3) that moves the wastes to a spring-loaded gate54. When the wastes are compacted to a degree that exceeds the holdingthreshold of the spring-loaded gate 54, the latter is shifted away underwaste pressure and lets the load to enter the interior of the retort 36.

In the pyrolysis reactor 24, the wastes are subjected to a pyrolysistreatment (Step 5) by being heated without access of oxygen to atemperature in the range of 800° C. to 1000° C. The product is conveyedfrom the loading side to the unloading side of the reactor 24 due torotation of the tapered screws 40 and 42 that converge in the horizontalplane and are inclined in the downward direction in the vertical plane.The material is transported through the space 60 (FIGS. 2 and 3) betweenthe threads of the screws 40 and 42 and at the same time is effectivelymixed by the rotation of the screws 40 and 42 (FIG. 4A).

As a result, of the pyrolysis, the treated product is decomposed into asolid phase (a mixture of carbon residue that contains coke and tar, anda gaseous phase (syngas). A part of the syngas developed in thepyrolysis reactor is sent to the waste drier and/or to the burners 68 a,68 b, . . . 68 n (FIG. 2) of the reactor for use as an additional heatcarrier. The coking carbon residue is sent to a centrifuge 70 c forpurification and separation of low-energy residue that does not containhydrocarbons and that could not be removed from the wastes at thesorting stage (Step 6). The carbon residue (with 2 to 10% of carbon) isthen sent back to the burners of the reactor 24 for afterburning.

From the pyrolysis reactor 24, the syngas is sent to the dry-cleaningunit 72, where the level of dust in the syngas is reduced (Step 7), andthe syngas is then passed through the first stage of the wet scrubberwhen the syngas is cleaned by a flow of water (Step 8) from tar andchlorine-, fluorine, and sulfur-containing admixtures. The syngas isthen fed to the second wet-stage of scrubbing with subsequent removal ofthe separated impurities with alkalis (Step 9). From the secondwet-stage cleaner, the syngas is sent to absorption (Step 10) where theCO₂-saturated aqueous solution is separated from the syngas wherefromthe gas is sent to a power-generation, e.g., a gas-turbine co-generator29 that generates electricity (Step 11).

From both wet-stages of scrubbing, the mixture of water with impuritiesis also sent to a floatator 78 that produces process water (Step 12)suitable for further appropriate use. Meanwhile, dehydrated tar andmixture of dehydrated impurities are sent to the centrifuge 70 c formixing with the coking carbonaceous residue of the pyrolysis process andfrom there to the reactor burners for afterburning.

The syngas purified from the tar and the chlorine-, fluorine, andsulfur-containing admixtures is fed to an absorber that produces aCO₂-saturated aqueous solution, which is sent to the disrober 77 withsubsequent decomposition of the solution into CO₂ and processing water.

Thus it has been shown that the invention provides a novel method andsystem for pyrolytic processing and more efficient utilization ofmunicipal and domestic wastes as compared to conventional methods andsystems of this type. The aforementioned system allows a high degree ofpurification of gas and more efficient generation of energy ingas-turbine co-generators. The system separates CO₂ from the syngas andutilizes the separated CO₂ as an additional commercial product alongwith decrease in concentration of harmful components in the gasexhausted to the atmosphere. The system does not require separatecollection of wastes of different types. The method and system of theinvention do not leave by-products such as a coking residue. The systemis capable of working in a self-contained mode and at the same timeproduces energy for external consumers.

Although the invention has been shown and described with reference tospecific embodiments, it is understood that these embodiments should notbe construed as limiting the areas of application of the invention andthat any changes and modifications are possible provided that thesechanges and modifications do not depart from the scope of the attachedpatent claims. For example, the retort and the external casing thatsurrounds the retort may have shapes different from those shown in thedrawings and can be made from different heat-resistant materials. Theloading and unloading mechanism of the pyrolysis reactor may havestructures different from those shown in FIG. 5. For example, anelectric driven can be used for opening and closing the sliding gates.The sliding gates may be replaced by rotating gates pivotally installedon the inner walls of the loading hopper.

1. A system for processing and utilizing municipal and domestic wastecomprising the following main modules connected in series: a wastepre-treatment and feed module, a pyrolysis reactor, a syngas cleaningmodule, and an energy generation unit, wherein the waste-pretreatmentand feed module comprises: a waste-sorting unit for sorting the wastesto be treated and for removing untreatable items; a waste-mixturegrinder for grinding the presorted wastes to produce ground wastes of apredetermined dimensions suitable for processing and utilization, thewaste-mixture grinder being connected to the waste-sorting unit; a dryerfor drying the ground wastes, the dryer being connected to thewaste-mixture grinder; and a dry-waste accumulator with a loadingmechanism and an unloading mechanism, the loading mechanism beingconnected to the dryer, and the unloading mechanism being connected tothe pyrolysis reactor that decomposes the wastes essentially into asyngas and solid products of pyrolysis; the syngas cleaning modulecomprises: a dry cleaner that contains a dust catcher and is connectedto the pyrolysis reactor for receiving the syngas produced in pyrolysis;a gas cooler for reducing the gas temperature; a wet-cleaning stageconnected to the gas cooler and that comprises a first wet syngascleaner connected to the gas cooler and intended for cleaning the syngaswith a flow of water, and a second wet syngas cleaner connected to thefirst wet syngas cleaner and intended for cleaning syngas with a flow ofan alkali solution; and an absorber that is connected to thewet-cleaning stage for receiving the syngas therefrom and for separatingat least a reusable gaseous carbon dioxide from the syngas; the systemfurther comprising: a floatator that is connected to the wet-cleaningstage and produces reusable water; a centrifuge which is connected tothe unloading mechanism of the pyrolysis reactor and is intended forpurification of the solid products of pyrolysis; and a disorber that isconnected to the absorber and has means for separating the CO₂-saturatedaqueous solution obtained from the absorber into CO₂ and processingwater.
 2. The system of claim 1, wherein the energy generation unit is agas-turbine co-generator that generates electrical energy.
 3. The systemof claim 1, wherein the loading mechanism and the unloading mechanismeach contains a double-gate structure comprising a first gate that hasmeans for switching between an open position and a closed position and asecond gate that has gate control means for switching between the openposition and the closed position, said gate control means operating sothat the second gate is closed when the first gate is opened and can beopened only when the first gate is closed and vice versa.
 4. The systemof claim 3, wherein the loading mechanism further comprises a feed screwlocated under the second gate for feeding the wastes that falls onto thefeed screw when the second gate is the open position.
 5. The system ofclaim 3, wherein said gate control means comprise a first pneumaticcylinder connected to the first gate and a second pneumatic cylinderconnected to the second gate, the first pneumatic cylinder and thesecond pneumatic cylinder operating in an alternating order.
 6. Thesystem of claim 5, wherein the loading mechanism further comprises afeed screw located under the second gate for feeding the wastes thatfalls onto the feed screw when the second gate is open to the pyrolysisreactor.
 7. The system of claim 3, wherein the energy generation unit isa gas-turbine co-generator that generates electrical and heat energy. 8.The system of claim 5, wherein the energy generation unit is agas-turbine co-generator that generates electrical and heat energy.
 9. Amethod for processing and utilization of commercial and domestic wastesby pyrolytic treatment comprising the steps of: sorting the untreatedwastes and separating at least metal, glass, and low-energy components;grinding the sorted wastes to a predetermined size; drying the groundwastes; sending the ground wastes to a pyrolysis reactor and subjectingthe ground wastes to pyrolytic treatment in the pyrolysis reactor underconditions of absence of oxygen to produce heat, syngas, and solidproducts of pyrolysis that contain at least a coke; subjecting the solidproducts of pyrolysis to centrifugal treatment for separating theuntreated components and sending these untreated components back to thepyrolytic treatment for afterburning; sending the syngas produced inpyrolysis reactor to dry cleaning and dust collecting; subjecting thesyngas obtained from the dry cleaning step to wet cleaning with water;subjecting the syngas obtained from the wet cleaning with water to wetcleaning with alkali; sending the syngas treated in the wet cleaning toa stage of absorption for separation of CO₂-saturated aqueous solution;sending the syngas from the stage of absorption to a power generationunit and using said syngas as a working medium in said power generationunit for generating power;
 10. The method of claim 9, further comprisingthe steps of: subjecting the mixture of water with impurities obtainedfrom the wet cleaning to floatation for obtaining reusable water and atleast tar; subjecting said at least tar to the centrifuging forreprocessing.
 11. The method of claim 9, further comprising the step ofsending the heat produced in the pyrolysis reactor back to the dryingstage and the coke produced in the pyrolysis reactor back to thepyrolytic treatment for afterburning.
 12. The method of claim 9, whereinsaid power generation unit is a gas-turbine co-generator and thegenerated power is an electrical and heat power.
 13. The method of claim10, wherein said power generation unit is a gas-turbine co-generator andthe generated power is an electrical and heat power.
 14. The method ofclaim 11, wherein said power generation unit is a gas-turbineco-generator and the generated power is an electrical and heat power.15. The method of claim 9, wherein said predetermined size does notexceed 50 mm.
 16. The method of claim 10, wherein said predeterminedsize does not exceed 50 mm.
 17. The method of claim 9, wherein thepyrolysis treatment is carried out at a temperature ranges from 800° C.to 1000° C.
 18. The method of claim 11, wherein the pyrolysis treatmentis carried out at a temperature ranges from 800° C. to 1000° C.
 19. Themethod of claim 16, wherein the pyrolysis treatment is carried out at atemperature ranges from 800° C. to 1000° C.
 20. The method of claim 16,wherein the pyrolysis treatment is carried out at a temperature rangesfrom 850° C. to 900° C.